A hepatitis C outbreak preceded the HIV outbreak among persons who inject drugs in Athens, Greece: Insights from a mathematical modelling study

HCV Cascade of Care in HIV/HCV Co-Infected Individuals: Missed Opportunities for Micro-Elimination

People living with HIV-HCV co-infection comprise a target group for HCV-micro-elimination. We conducted an HCV cascade of care (CoC) for HIV-HCV co-infected individuals living in Greece and investigated factors associated with different HCV-CoC stages. We analyzed data from 1213 participants from the Athens Multicenter AIDS Cohort Study. A seven-stage CoC, overall and by subgroup (people who inject drugs (PWID), men having sex with men (MSM), men having sex with women (MSW), and migrants], was constructed, spanning from HCV diagnosis to sustained virologic response (SVR). Logistic/Cox regression models were employed to identify factors associated with passing through each CoC step. Among 1213 anti-HCV-positive individuals, 9.2% died before direct-acting antiviral (DAA) availability. PWID exhibited higher mortality rates than MSM. Of 1101 survivors, 72.2% remained in care and underwent HCV-RNA testing. Migrants and PWID showed the lowest retention rates. HCV-RNA was available for 79.2% of those in care, with 77.8% diagnosed with chronic HCV. Subsequently, 71% initiated DAAs, with individuals with very low CD4 counts (<100 cells/μL) exhibiting lower odds of DAA initiation. SVR testing was available for 203 individuals, with 85.7% achieving SVR. The SVR rates did not differ across risk groups. In 2023, significant gaps and between-group differences persisted in HCV-CoC among HIV-HCV co-infected individuals in Greece.

Incidence of primary hepatitis C infection among people who inject drugs during 2012-2020 in Athens, Greece

One of the World Health Organization's targets for the 2030 viral hepatitis elimination strategy is to reduce new hepatitis C (HCV) infections. In Athens, Greece, people who inject drugs (PWID) have a high HCV prevalence, with increasing trends since the 2000s. This analysis aims to assess primary HCV incidence among PWID during 2012-2020. Two community-based interventions were implemented in 2012-2013 and 2018-2020 with repeated sero-behavioural surveys in each period. Participants enrolled in multiple surveys were identified through linkage. To assess trends in HCV transmission, three indicators were estimated: (i) anti-HCV prevalence among 'new' injectors (those injecting ≤2 years), (ii) indirect HCV incidence among 'new' injectors, assuming infection occurred at the midpoint between initiating injection and the first positive test, and (iii) HCV incidence from repeat participants. There were 431 and 125 'new' injectors, respectively, in 2012-2013 and 2018-2020. Αnti-HCV prevalence [95% CI] declined from 53.6% [48.8%, 58.3%] in 2012-2013 to 40.0% [31.3, 49.1%] in 2018-2020 (25.4% reduction, p = .007). The indirect estimate [95% CI] of HCV incidence among 'new' injectors decreased from 56.1 [49.3, 63.8] to 39.0/100 person-years (PYs) [29.6, 51.5] (30.5% reduction, p = .020). HCV incidence [95% CI] based on seroconversions in repeat participants (16/63 in 2012-2013 and 9/55 in 2018-2020) declined from 64.6 [39.6105.4] to 13.8/100 PYs [7.2, 26.5], respectively (78.6% reduction, p < .001). Primary HCV incidence remains high among PWID in Athens. Consistent implementation of combined interventions, including high-coverage harm reduction programs and initiatives tailored to increase access to HCV treatment, is essential to sustain the declining trends documented during 2012-2020.

Surveillance for endemic infectious disease outbreaks: Adaptive sampling using profile likelihood estimation

Outbreaks of an endemic infectious disease can occur when the disease is introduced into a highly susceptible subpopulation or when the disease enters a network of connected individuals. For example, significant HIV outbreaks among people who inject drugs have occurred in at least half a dozen US states in recent years. This motivates the current study: how can limited testing resources be allocated across geographic regions to rapidly detect outbreaks of an endemic infectious disease? We develop an adaptive sampling algorithm that uses profile likelihood to estimate the distribution of the number of positive tests that would occur for each location in a future time period if that location were sampled. Sampling is performed in the location with the highest estimated probability of triggering an outbreak alarm in the next time period. The alarm function is determined by a semiparametric likelihood ratio test. We compare the profile likelihood sampling (PLS) method numerically to uniform random sampling (URS) and Thompson sampling (TS). TS was worse than URS when the outbreak occurred in a location with lower initial prevalence than other locations. PLS had lower time to outbreak detection than TS in some but not all scenarios, but was always better than URS even when the outbreak occurred in a location with a lower initial prevalence than other locations. PLS provides an effective and reliable method for rapidly detecting endemic disease outbreaks that is robust to this uncertainty.

Interdisciplinary HIV Sentinel Case Review: Identifying Practices to Prevent Outbreaks in Philadelphia

INTRODUCTION

The Ending the HIV Epidemic in the U.S. initiative considers cluster and outbreak response essential. This article describes the design, implementation, and early findings of a Philadelphia-based project to systematically assess sentinel cases among priority populations for improving public health infrastructure and preventing future outbreaks.

METHODS

Sentinel HIV cases (i.e., early-stage or acute infection or molecular cluster cases) were identified among priority populations (Black and Hispanic/Latino men who have sex with men, youth aged 18-24 years, and transgender people who have sex with men). Chart abstraction and structured interview data were reviewed to determine themes and service gaps and to identify, prioritize, and implement recommendations. Interdisciplinary review teams included individuals with lived experience, frontline staff, and local agency leadership.

RESULTS

Data were collected during July 2019-December 2020 and analyzed for 53 of 126 sentinel cases of HIV diagnosed since July 1, 2018. The majority were men who have sex with men (79.3%), those aged 18-24 years (67.9%), and non-Hispanic Black (67.9%). More than half received sexually transmitted infection and HIV testing ≤3 years preceding HIV diagnosis (56.6% and 54.7%, respectively), had a healthcare visit within 12 months before diagnosis (64.2%), and had no evidence of pre-exposure prophylaxis awareness (58.5%). Project recommendations effectuated actions to improve pre-exposure prophylaxis provision, integrate sexually transmitted infection and HIV testing, and educate primary care providers.

CONCLUSIONS

HIV sentinel case review is a model for health departments to rapidly respond to recent transmission, identify missed HIV prevention opportunities, strengthen community partnerships, and implement programmatic and policy changes. Such efforts may prevent outbreaks and inform longer-term strategies.

Could the 2010 HIV outbreak in Athens, Greece have been prevented? A mathematical modeling study

INTRODUCTION

In 2009 and 2010, Athens, Greece experienced a hepatitis C virus (HCV) and a Human Immunodeficiency Virus (HIV) outbreak among People Who Inject Drugs (PWID), respectively. The HCV outbreak was not detected, while that of HIV was identified in 2011. The integrated HIV-interventions, launched in early 2012, managed to reduce directly the HIV incidence and indirectly the HCV incidence. This study aims to assess what would have been the course of the HIV outbreak and its associated economic consequences if the 2009 HCV outbreak had been detected and integrated interventions had been initiated 1- or 2-years earlier.

METHODS

The model was calibrated to reproduce the observed HIV epidemiological and clinical parameters among PWID of Athens, Greece. We examined the effect of the 1- or 2-years earlier detection scenarios, the 1-year later detection, the non-detection scenario, and compared them to the status quo scenario.

RESULTS

Cumulative HIV cases, under the status-quo scenario during 2009-2019, were 1360 (90% Credible intervals: 290, 2470). If the HCV outbreak had been detected 1- or 2- years earlier, with immediate initiation of integrated interventions, 740 and 1110 HIV cases could be averted by 2019, respectively. Regarding the costs, if there was an efficient notification system to detect the HCV outbreak 1 or 2 years earlier, 35.2-53.2 million euros could be saved compared to the status quo by 2019.

CONCLUSIONS

If the HCV outbreak had been detected and promptly addressed, the HIV outbreak would have been prevented and 35.2-53.2 million euros could have been saved.

The Past, Present, and Future of PrEP implementation Among People Who Use Drugs

PURPOSE OF REVIEW

Recent HIV outbreaks among people who use drugs (PWUD) necessitate additional HIV prevention tools. Pre-exposure prophylaxis (PrEP) is highly efficacious yet uptake among PWUD remains exceedingly low. To address multilevel, complex barriers to PrEP use among PWUD, a range of intervention strategies are needed.

RECENT FINDINGS

The literature on interventions to optimize PrEP use among PWUD is nascent, comprising small pilots and demonstration projects in early phases of intervention development. Initial studies suggest that structural, healthcare, interpersonal, and individual-level interventions can improve PrEP use for PWUD, and a number of efficacy trials are underway. Future studies are needed to optimize the use of new PrEP modalities (e.g., injectable PrEP), simultaneously target multilevel challenges to PrEP use, and evaluate the integration of PrEP into other service settings and substance use treatment modalities.

HIV prevention and treatment in Southern Europe in the aftermath of bailout programmes

BACKGROUND

The global financial crisis impacted public health in Europe, and had a particularly critical detriment to health systems in Southern Europe. We aim to describe HIV response and progress towards the current global HIV targets in specific Southern European countries, which received financial adjustment programmes.

METHODS

We examined and compared a set of HIV indicators in Cyprus, Greece, Portugal and Spain. The indicators included: (i) HIV epidemiology; (ii) adoption of WHO's 'Treat All' recommendation; (iii) progress towards the UNAIDS global targets of 90-90-90; (iv) adoption/implementation of pre-exposure prophylaxis (PrEP); and (v) adoption/implementation of WHO's HIV self-testing (HIVST) recommendation.

RESULTS

HIV incidence varied across countries since 2010, with sustained declines in Portugal and Spain, and marked increases in Greece and Cyprus. By 2016, all four countries have adopted WHO's 'Treat All' recommendation, leading to a marked increase in people receiving ART. Improvements were seen in all 90-90-90 targets, with Portugal achieving those in 2017, but Greece lagging somewhat behind, as of 2016. Portugal and Spain have also started implementing PrEP, and Greece has completed a pilot with no additional access to PrEP for pilot participants and no national programme in place. Cyprus has been the slowest in terms of adopting PrEP and HIVST.

CONCLUSIONS

Countries need to focus on prioritizing effective and comprehensive prevention measures, including HIVST and PrEP, and scale-up access to quality treatment and care for those diagnosed, in order to accelerate the reduction of new HIVs infections and successfully meet the global targets for HIV treatment.

The cost of a late-detected outbreak among people who inject drugs. A modeling study

BACKGROUND

People who inject drugs (PWID) are at risk for human immunodeficiency virus (HIV) and hepatitis C virus (HCV). In 2009 and 2011, Athens, Greece experienced an HCV and an HIV outbreak among PWID, respectively. Of these, only the 2011 HIV outbreak was detected. However, the public health interventions implemented in response to the HIV outbreak tackled also indirectly the undetected HCV outbreak. The aim of this study is to highlight the potential benefits of an efficient notification system using as a case study the undetected 2009 HCV outbreak among PWID of Athens. More specifically, the study assesses whether an earlier implementation of the same public responses could diminish the scale of the HCV outbreak and estimates the potential cost-savings.

METHODS

A previous dynamic, stochastic, individual-based model was used to simulate HCV transmission among PWID of Athens, Greece. We calibrated the model to reproduce the observed HCV prevalence. We examined the effect of the non-detection scenario, the 1- or 2-years earlier detection scenarios and compared them to the status quo scenario.

RESULTS

Under the non-detection scenario, 2800 additional PWID would have been infected with HCV compared to the status quo by 2019. On the contrary, if the outbreak was detected 1- or 2- years earlier with immediate interventions, 440 and 970 HCV cases could be averted by 2019, respectively. Non-detection of the outbreak would cost an additional 43.2 (95% Credible interval: 2.7, 59.4) million euros to the healthcare system, compared to the status quo. On the other hand, if there was an efficient notification system to detect the HCV outbreak 1 or 2 years earlier, 6.8-15.6 million euros could have been saved by 2019.

CONCLUSIONS

An efficient notification system among PWID is a cost-saving investment that could detect on time and contain future outbreaks, and save valuable resources of the healthcare system.